Contact-type magnetic head having an integral control portion for generating negative pressure

ABSTRACT

A magnetic head having a control portion provided integrally with an opposing surface located opposing the recording surface of a magnetic disc or a head mount for generating a negative pressure between the control portion and the magnetic disc to attract the magnetic disc towards the magnetic head, thereby generating an adequate and sufficient negative pressure in the vicinity of the magnetic head and achieving a good head touch. This configuration enables compact design of the mechanism and an increased recording area of the magnetic disc compared with the case in which a magnetic head and a negative pressure generation type stabilizing plate to attract the magnetic disc towards the magnetic head are separately disposed, and eliminates the need for procedures for separate positioning of the individual magnetic head and stabilizing plate, thereby achieving a considerable reduction in manufacturing steps and production cost.

This is a continuation of application Ser. No. 08/176,692 filed on Jan.3, 1994, now abandoned, which is a continuation of application Ser. No.07/720,323, filed Jun. 25, 1991, now abandoned, which is a continuationof application Ser. No. 07/461,508, filed Jan. 5, 1990, now U.S. Pat.No. 5,047,884, issued Sep. 10, 1991.

BACKGROUND OF THE INVENTION

This invention relates to a magnetic head comprising a control portionto generate a negative pressure, integrally formed on the surface of themagnetic head facing a magnetic disc, thereby achieving a good headtouch.

In a recording and reproduction device which uses a thin, flexiblemagnetic disc as a recording medium, when the magnetic head is simplycaused to come in contact against the magnetic disc, the magnetic disctends to be deformed by the pressure of the magnetic head and to comeout of the magnetic head, and stable contact is not obtained.

Heretofore, there has been an attempt in which a stabilizing plate isprovided in the vicinity of the magnetic head, which generates anegative pressure in the area where the magnetic head is located, toattract the magnetic disc towards the magnetic head side, therebyachieving a stable contact.

FIG. 17 is a schematic view showing structure of the prior art magneticdisc recording and reproduction device, and FIG. 18 is a schematicperspective view showing part of the device. Referring to these figures,a center core 14 mounted at the center of a magnetic disc 13 isdetachably attached to a drive shaft 12 of a drive motor 11 to rotatethe magnetic disc 13, and the magnetic disc 13 is rotated at apredetermined rotational speed by the rotation of the drive motor 11.

Below the magnetic disc 13 shown in the figures is disposed a magnetichead 15 which is capable of contacting against the recording surface ofthe magnetic disc 13 during recording and reproduction operation. Themagnetic head 15 is fixed to a carriage 17 engaged with a threaded shaft18 disposed along the radial direction of the magnetic disc 13 and, byrotating the threaded shaft 18 by a drive unit (not shown), the magnetichead 15 is moved in the radial direction of the magnetic disc 13 to scanthe recording surface.

The magnetic head 15 has a head mount fixed to the carriage 17 and ahead chip which is fixed to the end of the head mount and has a magneticgap on a surface opposing the magnetic disc 13, and the magnetic disc 13comes in sliding contact against the magnetic gap of the head chip toperform recording and reproduction.

Heretofore, the opposing surface having the magnetic gap is formed in asmoothly curved surface protruding towards the magnetic disc 13 sidealone the rotational direction (arrow R) and the radial direction of themagnetic disc 13 to prevent the recording surface of the magnetic disc13 from being damaged and to obtain a good head touch.

Furthermore, as shown in FIG. 19, below the magnetic disc 13, a pair ofstabilizing plates 19 are provided having inclined surfaces 18 of whichone end is located in the vicinity of a free rotary surface N at theupstream side with respect to the rotational direction (arrow R) of themagnetic disc 13 and inclined so as to gradually become more distantfrom the free rotary surface N towards the downstream side with respectto the rotational direction, with a gap 20 as a moving path of themagnetic head 15.

Thus, the stabilizing plates 19 generate a negative pressure in the areabetween the magnetic disc 13 and inclined surfaces 18 of the stabilizingplates 19 as the magnetic disc 13 rotates, whereby the negative pressureattracts the magnetic disc 13 towards the magnetic head 15 side to causethe magnetic disc 13 to contact the magnetic gap 24 of the head chip 22of the magnetic head 15. As a result, in the recording and reproductionoperation, the magnetic disc 13 always maintains a stable contact statewith the magnetic held 15.

Such negative pressure-generation type stabilizing plates are describedin detail, for example, in Japanese Patent Publication Laid-open No.61-9888/1986, Japanese Patent Publication Laid-open No. 60-219871/1985,and Japanese Patent Publication Laid-open No. 62-33380/1987.

In this Specification, the free rotary surface N refers to a rotarysurface of the magnetic disc 13 attached to the drive motor 11 of themagnetic disc recording and reproduction device, rotating with no actionof external forces other than the rotary driving force.

With the stabilizing plates 19 of a type as shown in FIG. 19, a gap 20for the magnetic head 15 and the carriage 17 to move the magnetic head15 is formed between the pair of the stabilizing plates 19. However,since negative pressure is generated by the stabilizing plates 19 mainlyin the area between the inclined surfaces 18 formed on the stabilizingplates 19 and the magnetic disc 13, the gap 20 is not concerned in thegeneration of negative pressure, but rather tends to reduce the negativepressure generated.

Therefore, the above configuration has been defective in that themagnetic disc 13 is attracted towards the inclined surfaces of pair ofstabilizing plates 19 located at both sides of the magnetic head 15, buttends to be floated up at the gap 20 where the magnetic head 15 islocated, resulting in insufficient contact of the magnetic disc 13 withthe magnetic head 15.

Furthermore, since the magnetic head 15 and the stabilizing plates 19are provided separately, it requires a very complex effort to preciselyposition the magnetic head 15 and the stabilizing plates 19, which canlead to an increase in cost.

OBJECT OF THE INVENTION

With a view to eliminate the above prior art problems of magnetic heads,it is a primary object of the present invention to provide a magnetichead which has a control member to generate an appropriate andsufficient negative pressure, thereby achieving a good head touch, aswell as simplified positioning of the magnetic head and the controlmember.

SUMMARY OF THE INVENTION

In accordance with the present invention which attains the above object,there is provided a magnetic head having an opposing surface locatedopposing the recording surface of a magnetic disc and a magnetic gapformed on the opposing surface, characterized by a control portionformed on the opposing surface to generate a negative pressure betweenthe member and the magnetic disc as the magnetic disc rotates, whichattracts the magnetic disc towards the magnetic gap side.

Thus, the control portion formed on the opposing surface of the magnetichead opposing the magnetic disc generates a negative pressure betweenthe magnetic disc and the control portion as the magnetic disc rotates,and the negative pressure attracts the magnetic disc towards themagnetic head side to cause the magnetic disc to come in sliding contactwith the magnetic gap formed on the opposing surface, thereby achievinga good head touch.

The control portion can be an inclined surface inclined to becomefarther from the free rotary surface of the magnetic disc towards thedownstream side with respect to the rotational direction of the magneticdisc, and the inclination of the inclined surface relative to the freerotary surface of the magnetic disc may be varied along the rotationaldirection of the magnetic disc. Furthermore, the control portion may beprovided with a groove along the rotational direction of the magneticdisc to increase generation of negative pressure and rectify the airflow.

There is also provided according to the present invention a magnetichead having a head mount and a head chip which is mounted to the headmount and has a head chip capable of coming in sliding contact againstthe magnetic disc, characterized by a control portion formed integrallywith the head mount for generating a negative pressure between thecontrol portion and the magnetic disc to attract the magnetic disctowards the head chip side.

Thus, as the magnetic disc rotates, the control portion formed on thehead mount generate a negative pressure between the control portion andthe magnetic disc to attract the magnetic disc towards the head chipside and cause the magnetic disc to come in sliding contact with thehead chip, thereby achieving a good head touch.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic perspective view showing an embodiment of themagnetic head according to the present invention.

FIG. 2 is a schematic cross sectional view taken along line 2--2 in FIG.1.

FIG. 3 is a schematic perspective view showing another embodiment of theinventive magnetic head.

FIG. 4 is a schematic cross sectional view taken along line 4--4 in FIG.3.

FIG. 5 is a schematic plan view showing another embodiment of theinventive magnetic head.

FIG. 6 is a schematic perspective view showing another embodiment of theinventive magnetic head.

FIG. 7 is a schematic cross sectional view taken along line 7--7 in FIG.6.

FIG. 8 is a schematic side cross sectional view showing anotherembodiment of the inventive magnetic head.

FIG. 9 is a schematic perspective view showing another embodiment of theinventive magnetic head.

FIG. 10 and FIG. 11 are schematic cross sectional views taken alonglines 10--10 and 11--11, respectively.

FIG. 12, FIG. 13 and FIG. 14 are schematic cross sectional views showingexamples of control members.

FIG. 15 and FIG. 16 are schematic perspective views showing otherembodiments of the inventive magnetic head.

FIG. 17 is a schematic side view showing a prior art recording andreproduction device.

FIG. 18 is a schematic perspective view showing part of the recordingand reproduction device shown in FIG. 17.

FIG. 19 is a schematic cross sectional view showing a prior artrecording and reproduction device.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A preferred embodiment of the present invention will now be described indetail with reference to the drawings. Since, in this embodiment, themounting position and mounting structure of the inventive magnetic headin the recording and reproduction device are same as in the prior art,the same members as used in the prior art are indicated using the samereference numbers, and description thereof is omitted.

Referring to FIG. 1 showing this embodiment, an end surface 31 of a headmount 21 is provided protrudingly with mounting members 32 to clamp ahead chip 22 and fix it integrally with the head mount 21, and the headchip 22 is integrally mounted to the mounting members 32. An opposingsurface 33 which comes in sliding contact with the recording surface ofa magnetic disc 13 is formed at the front end of the head chip 22opposing the recording surface of the magnetic disc 13.

At nearly the center of the opposing surface 33 is formed a plurality (2in this embodiment) of magnetic gaps 34, which come in sliding contactwith the recording surface of the magnetic disc 13 to make mediation(transmission and reception) of magnetic information, along nearly theradial direction of the magnetic disc 13. As shown in FIG. 2 which is aschematic cross sectional view taken along line 2--2 in FIG. 1, theopposing surface 33 is formed as an inclined surface 35 which isinclined so as to become more distant from the free rotary surface N ofthe magnetic disc 13 towards the downstream side with respect to therotational direction (arrow R) of the magnetic disc 13.

As a result, as the magnetic disc 13 rotates, a negative pressure isgenerated between the inclined surface 35 of the head chip 22 and themagnetic disc 13, which attracts the magnetic disc 13 towards the headchip 22 side and causes the magnetic disc 13 to come in sliding contactagainst the magnetic gap 34 provided at the end of the head chip 22,thereby achieving a good head touch.

Furthermore, an end portion 36 of the head chip 22 located at theupstream side of the magnetic disc 13 with respect to its rotationaldirection is made of a material harder than the head chip 22, such assapphire, to prevent abrasion due to sliding with the magnetic disc 13.

Referring to FIG. 3 showing another embodiment, a plurality (2 in thisembodiment) of magnetic gaps 34 are provided on the opposing surface ofthe head chip 22 opposing the magnetic disc 13 along nearly the radialdirection of the magnetic disc 13. On the opposing surfaces locatedrespectively at the upstream side and the downstream side of themagnetic gaps 34 with respect to the rotational direction of themagnetic disc 13 are provided an inclined surface 41 and an inclinedsurface 42. As shown in FIG. 4 which is a cross sectional view takenalong line 4--4 in FIG. 3, these incline surfaces 41 and 42 are formedso as to become farther from the free rotary surface N of the magneticdisc 13 towards the down stream side with respect to the rotationaldirection (arrow R) of the magnetic disc 13, and inclination angle θ₂ ofthe inclined surface 42 to the free rotary surface N is greater thaninclination angle θ₁ of the inclined surface 41 to the free rotarysurface N.

Preferable inclination angles θ₁ and θ₂ are, for example, θ₁ =1° to 3°,whereas θ₂ =2° to 6°, a value which is approximately double the value ofθ₁. Referring to FIG. 5 which is a schematic plan view of the head chip22 shown in FIG. 3, the size of the opposing surface of the head chip 22opposing the magnetic disc 13 is preferably to be at least l₁ =1.2 mmand l₂ =1.2 mm, where l₁ is the length of a side which is nearlyperpendicular to the rotational direction (arrow R) of the magnetic disc13 and l₂ is the length of a side along the rotational direction.

Therefore, as the magnetic disc 13 rotates, a negative pressure isgenerated in the area surrounded by the magnetic disc 13 and theinclined surfaces 41 and 42, which attracts the magnetic disc 13 towardsthe head chip 22 to come in sliding contact with the head chip 22.However, since the inclination angle of the inclined surface 42 locatedat the downstream side with respect to the rotational direction of themagnetic disc 13 is greater than the inclination angle of the inclinedsurface 41 located at the upstream side, the magnetic disc 13 isattracted by a greater negative pressure at the downstream side of themagnetic gap 34. As a result, the magnetic disc 13 is attracted whilebeing deformed at both sides of the magnetic gap 34, thus improvingtouching of the magnetic disc 13 to the magnetic gap 34.

In this embodiment, a plurality (3 in this embodiment) of grooves 43,which are formed along nearly the rotational direction of the magneticdisc 13 over both the inclined surfaces 41 and 42, are disposed alongnearly the radial direction of the magnetic disc 13. The grooves 43 areformed continuously from the upstream end of the inclined surface 41 tothe downstream end of the inclined surface 42, and have a nearlyarc-formed cross section so that the depth is zero at the upstream endand downstream end.

The grooves 43 absorb air flow of nearly radial direction other thanthat in the rotational direction (circumferential direction) which ismainly generated by the rotation of 13 of the magnetic disc 13, andcause it to flow along the rotational direction, thereby controlling airflow in nearly the radial direction which hinders generation of thenegative pressure. In addition, since the grooves 43 can expand the areabetween the magnetic disc 13 and the head chip 22, they can increase thenegative pressure generated in the area. Furthermore, the grooves 43also have an action to stabilize the air flow (forming a laminar flow)in the rotational direction of the magnetic disc 13, thereby evenfurther improving head touch of the magnetic disc 13.

Referring to FIG. 6 which is a schematic perspective view showinganother embodiment and to FIG. 7 which is a schematic cross sectionalview taken along line 7--7 in FIG. 6, the opposing surface of the headchip 22 opposing the magnetic disc 13 located at the upstream side ofthe magnetic gap 34 with respect to the rotational direction (arrow R)of the magnetic disc 13 has a flat surface 44 having a zero inclinationangle, that is, parallel to the free rotary surface N of the magneticdisc 13. At the front end of the head chip 22 located at the downstreamside of the magnetic gap with respect to the rotational direction of themagnetic disc 13 is provided a smooth inclined curved surface 45 formedso that it becomes gradually more distant from the free rotary surface Nof the magnetic disc 13 towards the downstream side with respect to therotational direction of the magnetic disc 13.

The inclined curved surface 45 has a plurality (2 in this embodiment) ofgrooves 46, which are formed along nearly the rotational direction ofthe magnetic disc 13 and disposed at both sides of the magnetic gap 34along nearly the rotational direction of the magnetic disc 13. Thegrooves 46, which have depths of zero at the upstream end of theinclined curved surface 45 and have predetermined depths at thedownstream end of the inclined curved surface 45, communicate with thedownstream side area of the head chip 22. The groove 46 preferably havea maximal depth of 50 μm. In this embodiment, the flat surface 44parallel to the free rotary surface N of the magnetic disc 13 is formedon the opposing surface of the head chip 22 opposing the magnetic disc13. Alternatively, however, an inclined curved surface 47 may be formed,for example, as shown in FIG. 8, over the entire opposing surface, whichis gradually inclined so as to become more distant from the free rotarysurface N towards the downstream side with respect to the rotationaldirection of the magnetic disc 13.

In this case, where distance between the magnetic gap 34, which islocated nearly at the center of the inclined curved surface 47, and thefree rotary surface N is h₁, and distance between the downstream end ofthe inclined curved surface 47 and the free rotary surface N is h₂, itis preferable to set, for example, to h₁ =0 to 100 μm and h₂ =200 μm,or, as shown by dot-bar lines in the figure, position of the inclinedcurved surface 47 is moved parallelly by 0 to 200 μm towards the freerotary surface N side to position part or the entire of the inclinedcurved surface 47 above (in the figure) the free rotary surface N.

Thus, as the magnetic disc 13 rotates, a negative pressure is generatedin the area between the magnetic disc 13 and the inclined curved surface45 or 47, which attracts the magnetic disc 13 towards the front end ofthe head chip 22 to cause the magnetic disc 13 to come in slidingcontact with the magnetic gap 34, and the groove 46 absorbs the air flowin nearly the radial direction of the magnetic disc 13 to increase thenegative pressure and regulates the entire air flow generated inassociation with the rotation of the magnetic disc 13 to be a laminarflow, thereby achieving a stable head touch.

In the above described embodiments, the inclined surfaces 41 and 42, orthe flat surface 44 and the inclined curved surface 45, are individuallyformed at the upstream side and the downstream side of the magnetic gap34. However, position of the magnetic gap 34 may be shifted from theboundary of the inclined surface 41 and the inclined surface 42, or thatof the flat surface 44 and the inclined curved surface 45. Or, anincreased number (3 or more) of inclined surfaces with differentinclination angles to the free rotary surface N of the magnetic disc 13may be formed on the opposing surface of the head chip 22 opposing themagnetic disc 13 along the rotational direction of the magnetic disc 13.Thus, inclination angle of the inclined surface to the free rotarysurface N of the magnetic disc 13 may be varied along the rotationaldirection of the magnetic disc 13.

Furthermore, shapes and positions and number of the grooves 43 and 46are not restricted to those of the embodiments, but it is only requiredthat these grooves are formed on the opposing surface of the head chip22 opposing the magnetic disc 13 along the rotational direction of themagnetic disc 13.

An example of the magnetic head 15, which is fabricated for use in arecording and reproduction device for a 2-inch magnetic video floppydisc, uses a head chip which is almost the same as the head chip 22shown in FIG. 6. The head chip 22 has an approximately 2-mm square crosssection, the inclined curved surface 45 is formed on the part of about3/4 the area at the downstream side of the head chip 22, the twomagnetic gaps 34 are formed with an approximately 100 μm spacing and arepositioned at nearly the center of the front end of the head chip 22. Inexperiments, this magnetic head has been confirmed to achieve a verygood head touch.

FIG. 9 is a schematic perspective view of another embodiment of theinventive magnetic head, and FIG. 10 is a schematic cross sectional viewof the head chip 22 taken along line 10--10 in FIG. 9, that is, alongthe rotational direction (arrow R) of the magnetic disc 13. Referring toFIG. 9 and FIG. 10, an opposing surface 48 of the head chip 22 opposingthe magnetic disc 13 is inclined, for example, with a curvature radiusof r₁, to gradually become more distant from the free rotary surface Nof the magnetic disc 13 along the rotational direction of the magneticdisc 13. On the other hand, as shown in FIG. 11 which is a schematiccross sectional view of the head chip 22 taken along line 11--11, thatis, along the radial direction of the magnetic disc the opposing surface48 of the head chip 22 is inclined, for example, with a curvature radiusr₂, so that the magnetic gap 34 is at the top.

Therefore, the opposing surface 48 of the head chip is a nearlyspherical curved surface with the magnetic gap 34 at the top and, whenr₁ and r₂ are set almost equally, its curvature radius may be, forexample, approximately 50 to 150 mm. Alternatively, however, r₁ and r₂may be set differently so that the cross sectional edge of the head chip22 is straight along the radial direction of the magnetic disc 13, thatis, r₂ =∞. Thus, a control portion is formed on the opposing surface 48of the head chip 22 opposing the magnetic disc 13 which, with high-speedrotation of the magnetic disc 13, generates a negative pressure betweenthe control portion and the magnetic disc 13 to attract the magneticdisc 13. Furthermore, grooves as previously described with reference toFIG. 3 and FIG. 8 may be formed on the opposing surface 48 along therotational direction of the magnetic disc 13 to regulate air flow andpromote generation of negative pressure.

The head chip 22 thus provided with the negative pressure generatingcontrol portion may have such dimensions as shown in FIG. 9 in which l₁is at least about 1.2 mm and l₂ is at least about 1.2 mm, where l₂ isthe length of a side along the rotational direction of the magnetic disc13 and l₁ is the length of a side perpendicular to the rotationaldirection.

Thus, in the inventive magnetic head 15, the control portion, which hasthe same function as the stabilizing plate, is provided integrally onthe opposing surface of the very small head chip 22 opposing themagnetic disc 13 to ensure the head touch, thereby enabling veryefficient utilization of the recording surface of the magnetic disc 13.For example, when the above-described 2-mm square head chip 22 isapplied to a 2-inch magnetic video floppy disc, the floppy disc has adiameter of about 23.5 mm, which is subtracted by a center hub diameterof about 9 mm, 2 mm for the head chip 22, and an allowance of 1 mm (atotal of 2 mm for the diameter) at the periphery of the floppy disc, thefloppy disc has an effective diameter of 10.5 mm, which enablesformation of about 105 tracks.

Since the use of the inventive magnetic head 15 eliminates the need forthe negative pressure generation type stabilizing plate 19 separate fromthe magnetic head 15, positioning of the individual magnetic head 15 andthe stabilizing plate required for prior art systems can be eliminated,thereby enabling very simplified production procedures.

In order to even further improve the head touch of the magnetic head 15,it is also possible to combine the magnetic head 15 with an auxiliarycontrol member. In an example of such configuration as shown in FIG. 12,a positive pressure generating control member 49 is disposed at theopposite side of the head chip 22 of the inventive magnetic head 15 withrespect to the free rotary surface N of the magnetic disc 13 and at theupstream side of the rotational direction (arrow R) of the magnetic disc13. As the magnetic disc 13 rotates, a positive pressure is generatedbetween the control member 49 and the magnetic disc 13 which pushes themagnetic disc 13 towards the magnetic head 15 side, thereby even furtherimproving the effect of the above-described various types of negativepressure generation type control portion formed on the head chip 22 atthe end of the magnetic head 15.

In another example, as shown in FIG. 13, a control member 50 is disposedat the same side as the magnetic head 15 with respect to the free rotarysurface N of the magnetic disc 13 and at the upstream side of themagnetic magnetic head 15 with respect to the rotational direction ofthe magnetic disc 13. In association with rotation of the magnetic disc13, a negative pressure is generated between the control member 50 andthe magnetic disc 13 to attract the magnetic disc 13 towards themagnetic head 15 side, thereby even further improving the effect of theabove-described various types of negative pressure generation typecontrol members formed on the head chip 22 at the end of the magnetichead 15.

Alternatively, as shown in FIG. 14, the positive pressure generationtype control member 49 shown in FIG. 12 may be formed as a plate spring51. In this case, a positive pressure is generated between the magneticdisc 13 and the plate spring 51 to push the magnetic disc 13 towards themagnetic head 15 side and, at the same time, the magnetic disc 13 isalso pushed towards the magnetic head 15 side by the urging force of theplate spring 51. Therefore, the end of the plate spring 51 at themagnetic disc 13 side, which may come in contact against the magneticdisc 13, is provided with a pad 52 to protect the magnetic disc 13 fromdamaging. However, the previously-described control members 49 and 50and the plate spring 51 are not necessarily required.

Referring to FIG. 15 which is a schematic perspective view showinganother embodiment, a ring-formed control member 61 surrounding the headchip 22 is formed integrally with the head mount 21 on a front surface31 of the head mount 21. This control member 61, as the magnetic disc 13rotates, generates a negative pressure in the area between a groove 62,which is formed by the inner peripheral surface of the ring-formedcontrol member 81 and the front surface 31 of the head mount 21, and themagnetic disc 13 to attract the magnetic disc 13 towards the head chip22 side and cause it to come in sliding contact against the magnetic gap34 of a sliding surface 33, thereby achieving a stable head touch. Inaddition, an inclined surface formed to become more distant from thestandstill magnetic disc 13 towards the inner periphery of a frontsurface 63 of the control member 61 can be provided, thereby varying themagnitude of the negative pressure generated.

The magnetic head 15, which is provided with the head mount 21, the headchip 22, and the control member 61, can be mounted to the carriage 17 orthe like as in the case of prior art systems, and can be moved on therecording surface of the magnetic disc 13 by moving the carriage 17.With the negative pressure generation type control member 61 disposed inthe vicinity of the head chip 22, generation of negative pressure byother control members having the same effect positioned farther from thehead chip 22 can be improved, thereby achieving an improved head touch,and both the head chip 22 and the control member 34 can be previouslypositioned precisely to the head mount 21, thereby considerably reducingthe positioning procedure with improved positioning precision overpositioning adjustment of the individual members.

Referring to FIG. 16 which is a schematic view showing anotherembodiment, in place of the ring-formed control member 61 used in theabove embodiment, a control member 65, which has inclined surfaces 64individually formed on the side opposing the magnetic disc 13 at theupstream side and the downstream side of the head chip 22 with respectto the rotational direction (arrow R) of the magnetic disc 13, isprotrudingly provided on the front surface 31 of the head mount 21.These inclined surface 64 are formed to become gradually more distantfrom the recording surface of the magnetic disc 13 towards thedownstream side with respect to the rotational direction of the magneticdisc 13. As the magnetic disc 13 rotates, a negative pressure isgenerated between the inclined surfaces 64 and the magnetic disc 13 toattract the magnetic disc 13 towards the head chip 22 side and cause itto come in sliding contact against the magnetic gap 34 of the slidingsurface 33.

In the embodiments shown in FIG. 15 and FIG. 16, the ring-formed controlmember and the control member having inclined surfaces 37 areindividually used as control members. However, configuration of thecontrol member is not restricted to these embodiments, but any types ofcontrol members can alternatively be used which are formed integrallywith the head mount 21 to generate a negative pressure between themember and the magnetic disc 13 in association with rotation of themagnetic disc 13 and attract the magnetic disc 13 towards the head chip22 side.

We claim:
 1. A magnetic head, having an opposing surface for location ina radial direction of a magnetic disc and opposite a recording surfaceof said magnetic disc which defines a free rotary plane when rotated ina rotational direction, and a magnetic gap formed on said opposingsurface, said head comprising:a control means, formed on said opposingsurface, for generating a negative pressure between said control meansand said magnetic disc as said magnetic disc rotates, and for attractingsaid magnetic disc towards said magnetic gap to come into continuoussliding contact with said magnetic head, wherein said control means isan inclined surface inclined to gradually become more distant from thefree rotary plane of said magnetic disc towards a downstream side withrespect to the rotational direction of said magnetic disc, wherein aninclination angle of said inclined surface relative to said free rotaryplane of said magnetic disc is varied along the rotational direction ofsaid magnetic disc, and wherein said control means is provided with atleast one groove bounded on each side by a respective side ridge andformed along the rotational direction of said magnetic disc, said atleast one groove being in a plane parallel to said rotational directionand perpendicular to said radial direction, and wherein said at leastone groove has a concave arc shape bowing away from said magnetic disccontinuously from a most upstream side of the magnetic head to a mostdownstream side of the magnetic head.
 2. The magnetic head of claim 1wherein said at least one groove includes a plurality of parallelgrooves formed along the rotational direction of said magnetic disc.